Rotary piston internal combustion engine

ABSTRACT

A circular piston internal combustion machine with trough-shaped depressions in the circumferential direction of the piston, in which fuel flow deflecting means are provided in said troughshaped depressions for deflecting the fuel flow in the axial direction of the piston which is rotatable relative to the housing.

United States Patent [72] Inventor Erwin I-Iejj Essen, Germany [2]] Appl. No. 812,524 [22] Filed Mar. 4, 1969 [45] Patented Oct. 5, 1971 [73] Assignee Fried Krupp Gesellschaft mit beschrankter Haftung Essen, Germany [32] Priority Mar. 6, 1968 [33] Germany 31 P16 01821.6

[54] ROTARY PISTON INTERNAL COMBUSTION ENGINE 1 Claim, 10 Drawing Figs.

[52] US. Cl 123/8119, 418/61 Primary ExaminerAllan D. Herrmann AttorneyWalter Becker ABSTRACT: A circular piston internal combustion machine with trough-shaped depressions in the circumferential direction of the piston, in which fuel flow deflecting means are provided in said trough-shaped depressions for deflecting the fuel flow in the axial direction of the piston which is rotatable relative to the housing.

PATENTEU GET 5197i 3,610,209

sum 1 [1F 3 Z 24 i Z 5] kl i 7/?/////////- yaw lnven tor ROTARY PISTON INTERNAL COMBUSTION ENGINE The present invention relates to a circular piston internal combustion machine with a stationary housing which comprises a housingmantle, the inner Surface of which in a section transverse to the axis of rotation of the piston relative to the housing has the shape of a multiarc epitrochoid and also comprises side portions which together with the housing mantle define an inner chamber. Extending through this inner chamber perpendicularly to the side portions thereof extends an eccentric shaft, the eccentric of which has rotatably journaled thereon a polygonal piston the flanks of which are provided with fuel chamber forming depressions extending in the circumferential direction of the piston.

With heretofore known circular piston internal combustion machines, the preparation of the fuel air mixture encounters considerable difficulties. The fuel gas flow is driven by the circulating piston against the outer wall of the working chamber without a sufficient turbulence of the fuel air mixture being obtained. The limited compression ratio and the longitudinal extending shape of the working chambers will not permit the provision of sufficiently large fuel chamber depressions similar to those customary with reciprocating pistons.

Various suggestions have been made to aid the development of turbulence. Thus, according to German Pat. No. 1,233,651, inserts have been placed in the suction passage, and according to the German Pat. No. 1,238,712 and the German Gebrauchsmuster l,963,642 it has been suggested to blow in air or an air fuel mixture during the suction and compression stroke. A particular motion control disclosed in the British Pat. No. 967,983 is intended to make possible the provision of deeper fuel chamber depressions. U.S. Pat. No. 3,196,852 suggests a fuel injection against the piston.

It is an object of the present invention to provide a circular piston internal combustion machine in which the preparation of the mixture of mixture compressing and air compressing circular piston internal combustion machines will be improved in a more simple and expedient manner.

It is another object of this invention to provide a circular piston internal combustion machine which will provide an improved combustion and a better economy of the fuel consumption.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 is a top view of a piston flank with a deflecting body in the fuel chamber depression.

FIG. 2 shows a longitudinal section through the piston flank of FIG. I and FIG. 2a shows further detail of an eccentric provided on a shaft journaled in a housing.

FIG. 3 illustrates a modified piston flank which differs from that of FIG. 1 primarily in that it is provided with two deflecting bodies in the fuel chamber depression.

FIG. 4 is a top view of a piston flank with a deflecting body having a declining surface in the fuel chamber depression.

FIG. 5 shows a longitudinal section through the piston flank of FIG. 4.

FIG. 6 is a top view of a modified piston flank in which the fuel chamber depression has a plurality of branches and FIG. 6a shows a longitudinal section through the piston flank of FIG. 6.

FIG. 7 represents in top view a further modification of a piston flank according to the invention which differs from the other modifications primarily in that it is provided with turbulence chambers and FIG. 7a shows a longitudinal section through the piston flank of FIG. 7.

The circular piston internal combustion machine according to the present invention is characterized primarily in that the fuel chamber depressions are provided with deflecting surfaces extending substantially perpendicularly with regard to the direction of rotation of the piston, for deflecting the fuel gas. Such an arrangement brings about that above all the additional fuel gas flow which is brought about in addition to the fuel gas flow inherent to the rotation of the piston in view of the varying spacing between the piston flank and the housing contour, will be made use of for preparing the mixture. This is due to the fact that the course of the flow and of the speed are determined primarily by the shape of the fuel chamber depression. At the respective place of minimum distance between housing contour and piston flank, a speed maximum occurs which means an additional flow. With regard to the piston flank, this speed maximum moves counter to the direction of flow from one piston corner to the other. This additional flow will, when the fuel chamber trough is designed in a flow favoring manner, for instance when the cross-sectional shape of the fuel chamber depression remains uniform over its entire length, not improve the turbulence of the mixture. However. such improvement has been obtained by the deflecting surfaces according to the present invention by means of which the fuel gas flow is deflected in a a shocklike manner and is subjected to turbulence. This effect will be further improved and increased if each fuel chamber depression is provided with a plurality of serially arranged deflecting surfaces and/or with deflecting surfaces arranged adjacent to each other. Expediently, the deflecting surfaces are formed by the faces of deflecting bodies in the central portion of the fuel chamber depressions, and the fuel chamber depressions are correspondingly widened within the region of the deflecting bodies.

In conformity with a further development of the invention, the surface of the deflecting body in the direction of rotation of the piston is so designed that it drops toward the bottom of the fuel chamber depression so that a deflection of the fuel gas flow will also be obtained in radial direction.

The course of the flow and of the speed are particularly favorably influenced by so designing the fuel chamber depressions that they are angled off a plurality of times along their length and/or provided with branches preferably at the start and at the end of the said fuel chamber depression. This angling off may consist of two parallel spaced branches which merge in a central portion of a somewhat greater width than the branches, the deflecting surfaces being formed by the wall portions which at the merging areas are at least approximately perpendicular to the direction of rotation of the piston.

According to a further development of the invention, turbulence chambers are arranged at the deflecting points for the fuel, which turbulence chambers are not directly passed through by fuel. The thus effected reduction in the flow velocity with simultaneous strong turbulence and recirculation will assure a satisfactory preparation of the fuel air mixture and will create favorable igniting conditions. It is for this reason that the turbulence chambers should be associated with the ignition source in such a way that the turbulence chambers will during the ignition be located in the region of the source of ignition. With air compressing machines, this effect can be taken advantage of in a particularly effective manner if, at least during the starting, the injection of a portion of the respective fuel quantity into the turbulence chamber is effected.

Referring now to the drawings in detail, a deflecting body 3 is inserted into the fuel chamber depression I, which fuel chamber depression is located in the piston flank generally designated 2a of the rotary piston 2 having edge means 2' which rotates in the direction of the arrow A about axis of a shaft 2" provided with an eccentric 2". The fuel gas flow impacts upon and perpendicularly to the face side 4 of the deflecting body 3, which fuel gas flow which with the piston position corresponding to the compression maximum will at the lobe portion 5 of the housing contour 6 reach its maximum speed. In this way the fuel gas flow is divided and deflected. The short arrows indicated in FIG. 1 illustrate the course of the flow of the fuel gas. Laterally and rearwardly of the deflecting body 3 which preferably tapers in the direction of movement of the piston, and due to the course of the longitudinal walls 7, a quieting down of the fuel gas flow and a distribution in width of said fuel gas flow will occur.

The fuel chamber depression 1 according to FIG. 3 is provided with two serially arranged deflecting bodies 3. in this way there will be obtained an increase in the region of the piston position over which the creation of a turbulence of the fuel gas flow will be favored.

The deflecting body 3 according to FIGS. 4 and 5 flares in the direction of rotation of the piston and additionally is provided with an inclined surface 8. It will be appreciated that with this design, in addition to a lateral deflection of the fuel gas flow at the face side 4, also at the depression transverse wall 9, a turbulence will be produced in radial direction.

The front and rear portion of the fuel chamber depression illustrated in FIG. 6 is formed by two parallel branches l0 and ll. The central portion consists of a single trunk 12. In view of the angled-off portions at the merging areas, the respectively rearwardly facing walls (when considering the direction of rotation of the piston) form the deflecting surfaces 13 and 14 for the fuel gas flow.

With the fuel chamber depression shown in FIG. 7, only the rear end portion R (when looking in the direction of rotation of the piston) of the fuel chamber depression is provided with parallel branches extending away from front end portion F. At the merging areas with the trunk 12, bulged portions 15 are provided which form turbulence chambers. The deflection, retardation and turbulence of the fuel gas flow will be further increased by the turbulence chambers 15.

As will be evident from the above, the deflecting walls according to the present invention, individually or in combination with each other, bring about the further advantage that the correspondingly equipped rotary piston internal combustion machines can be operated over an extended fuel air mixture range while at the same time the proportion of the nonburned parts in the exhaust gases will be reduced and also the knock sensitivity will be reduced. Moreover, with air compressing machines, a larger portion of the air load will be made use of in connection with the combustion which means that the fuel economy will be increased.

It is, of course, to be understood that the present invention is, by no means, limited to the particular showing in the drawings, but also comprises modifications within the scope of the appended claims.

While the piston of FIG. 2 is intended to be a triangular piston similar to the one disclosed in U.S. Pat. No. 3,319,610, also other polygonal pistons may be used in connection with the present invention.

What I claim is:

l. A rotary piston internal combustion machine which includes a stationary housing with an epitrochoidal inner contour, a shaft joumaled in said housing and provided with an eccentric, a rotary piston rotatable relative to said inner contour of said housing and joumaled on said eccentric for rotation relative thereto, said piston being of polygonal cross-sectional shape so as to have a plurality of circumferentially spaced edge means extending in the direction of the axis of rotation of said piston relative to said housing, said piston having those areas thereof which are located between said edge means and face said inner contour of said housing respectively provided with trough-shaped depressions forming combustion chambers and extending in the circumferential direction of said piston, each of said combustion chamber means located between two circumferentially successive edge means including wall means having deflecting surface means extending substantially transverse to the direction of rotation of said piston relative to said housing for deflecting fuel gas in said chamber means turbulently in a direction transverse to the circumferential direction of said rotary piston, said chamber means having a plurality of branches branched off laterally over its length, the branched-off portions of said chamber means being located at the front and rear end portions of said chamber means and being substantially parallel to each other, said branched-off portions comprising the deflecting wall means. 

1. A rotary piston internal combustion machine which includes a stationary housing witH an epitrochoidal inner contour, a shaft journaled in said housing and provided with an eccentric, a rotary piston rotatable relative to said inner contour of said housing and journaled on said eccentric for rotation relative thereto, said piston being of polygonal cross-sectional shape so as to have a plurality of circumferentially spaced edge means extending in the direction of the axis of rotation of said piston relative to said housing, said piston having those areas thereof which are located between said edge means and face said inner contour of said housing respectively provided with trough-shaped depressions forming combustion chambers and extending in the circumferential direction of said piston, each of said combustion chamber means located between two circumferentially successive edge means including wall means having deflecting surface means extending substantially transverse to the direction of rotation of said piston relative to said housing for deflecting fuel gas in said chamber means turbulently in a direction transverse to the circumferential direction of said rotary piston, said chamber means having a plurality of branches branched off laterally over its length, the branched-off portions of said chamber means being located at the front and rear end portions of said chamber means and being substantially parallel to each other, said branched-off portions comprising the deflecting wall means. 